Module 6

Question 1

Strong Acids

Answer 1

Fully ionise
Strong electrolyte conductors
–>

Question 2

Names of strong acids

Answer 2

HCl
HBr
HI
H2SO4
HNO3
HCLO4,3
SO I Have NO Clean Clothes

Question 3

Weak Acids

Answer 3

Partially ionises
-><-

Question 4

Strong Bases

Answer 4

Fully ionises

Question 5

Names of Strong Bases

Answer 5

NaOh, KOH, Ca(OH)2, Ba(OH)2
NO KO CO BO

Question 6

Weak Bases

Answer 6

Partially
To show their basic behaviour first show the dissolution of the base irreversible
1.) Na2CO3 –> 2Na+ + CO2-3
2.) Co2-3 + H2O -><- HCO-3 +OH -

Question 7

Ka

Answer 7

Equilibrium constant for ionisation of acid into a hydrogen ion
If triprotic, then mutiple ka’s for each disassociation

Question 8

How do indicators work?

Answer 8

Weak acids and bases

Question 9

Methyl Orange

Answer 9

Low pH (acidic) red
High pH (basic) yellow
Range: 3.1-4.4

Question 10

Litmus

Answer 10

4.5-8.3

Question 11

Bromothymol Blue

Answer 11

Low pH (acidic) Yellow
High pH (basic) Blue
Range: 6.0-7.6

Question 12

Phenolphthalein

Answer 12

Low pH (acidic) colourless
High pH (basic) pink
Range: 8.2-10.0

Question 13

Why use BaSO4?

Answer 13

White solid
Neutral white background to see colour change seeping through soil

Question 14

Metal hydroxide and acid reaction

Answer 14

BASH2O

Question 15

Acid and Metal Carbonate

Answer 15

CASH2OCO2

Question 16

Acid and Ammonia

Answer 16

Special case: does not contain oxygen but is an acidic, and instead will only produce ammonium salt

Question 17

Enthalpy of neutralisation

Answer 17

negative - exothermic

Question 18

Lavoisier

Answer 18

1st
Acids contain oxygen

Question 19

Davy

Answer 19

2nd
Acids contain. hydrogen
Doesn’t explain why e.g. ch4 is not acidic

Question 20

Liebig

Answer 20

3rd
Acids contain hydrogen which is replaced by a metal

Question 21

Arrhenius

Answer 21

4th
Acid: ionises in water to produce hydrogen ions
Base: ionises in water to produce hydroxide ions

Question 22

Limitations of Arrehenius

Answer 22

• Ammonia

Question 23

Brønsted-Lowry

Answer 23

Acid: proton donor
Basez: proton acceptor

Question 24

Limitations of Brønsted-Lowry

Answer 24

Cannot explain reactions with acidic oxides or basic oxides e.g. CaSO4

Question 25

Conjugate base of weak acid

Answer 25

strong conjugate base

Question 26

Will a solution of KF be acidic or basic?

Answer 26

1. KF --> K+ F- 2. F- + H2O --><-- OH- + HF So basic

Question 27

Degree of Ionisation

Answer 27

%ionised: [H+] eqm/[HA]ini *100

Question 28

pH after dilutions for strong acid/bases

Answer 28

c1v1=c2v2

Question 29

pH of solutions after mixing (Strong acid and Strong acid or base/base)

Answer 29

Total moles of h+ or OH- is the sum *don't forget volume)

Question 30

pH after neutralisation

Answer 30

Subtract acid and base * keep in mind which is xs * keep in mind volume

Question 31

Buffer

Answer 31

Resist changes in pH when small amounts of a/b are added Exists in equilibrium

Question 32

How are buffers made?

Answer 32

Mixing a weak acid and its conjugate base of weak base and conjugate acid

Question 33

Blood Buffer

Answer 33

H2CO3/HCO-3